The role of substrate wettability in nanoparticle transfer from wrinkled elastomers: fundamentals and application toward hierarchical patterning.

We report on the role of surface wettability during the printing transfer of nanoparticles from wrinkled surfaces onto flat substrates. As we demonstrate, this parameter dominates the transfer process. This effect can further be utilized to transfer colloidal particles in a structured fashion, if the substrates are patterned in wettability. The resulting colloidal arrangements are highly regular over macroscopic surface areas and display distinct pattern features in both the micrometer and nanoscale regime. We study the obtained structures and discuss the potential of this approach for creating hierarchical particle assemblies of high complexity. Our findings not only contribute to a better understanding of technologically relevant colloidal assembly processes, but also open new avenues for the realization of novel materials consisting of nanoparticles. In this regard, the presented structuring method is especially interesting for the design of optically functional surface coatings.